<html><!-- Created using the cpp_pretty_printer from the dlib C++ library.  See http://dlib.net for updates. --><head><title>dlib C++ Library - fonts_abstract.h</title></head><body bgcolor='white'><pre>
<font color='#009900'>// Copyright (C) 2005  Davis E. King (davis@dlib.net), Nils Labugt, Keita Mochizuki
</font><font color='#009900'>// License: Boost Software License   See LICENSE.txt for the full license.
</font><font color='#0000FF'>#undef</font> DLIB_FONTs_ABSTRACT_
<font color='#0000FF'>#ifdef</font> DLIB_FONTs_ABSTRACT_

<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../gui_core.h.html'>../gui_core.h</a>"
<font color='#0000FF'>#include</font> <font color='#5555FF'>&lt;</font>string<font color='#5555FF'>&gt;</font>
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../serialize.h.html'>../serialize.h</a>"
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../unicode.h.html'>../unicode.h</a>"
<font color='#0000FF'>#include</font> <font color='#5555FF'>&lt;</font>iostream<font color='#5555FF'>&gt;</font>

<font color='#0000FF'>namespace</font> dlib
<b>{</b>

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'>class</font> <b><a name='letter'></a>letter</b> 
    <b>{</b>    
        <font color='#009900'>/*!
            WHAT THIS OBJECT REPRESENTS
                This object represents a letter in a font.  It tells you the nominal 
                width of the letter and which pixels form the letter.

            THREAD SAFETY
                const versions of this object are thread safe but if you are going to
                be modifying it then you must serialize access to it.
        !*/</font>
    <font color='#0000FF'>public</font>:
        <font color='#0000FF'>struct</font> <b><a name='point'></a>point</b> 
        <b>{</b>
            <font color='#009900'>/*!
                WHAT THIS OBJECT REPRESENTS
                    This object represents one of the pixels of a letter.  
                    
                    The origin (i.e. (0,0)) of the coordinate plane is at the left 
                    side of the letter's baseline.  Also note that y is negative when 
                    above the baseline and positive below (it is zero on the baseline 
                    itself).

                    The x value is positive going to the right and negative to the left.
                    The meaning of a negative x value is that any points with a negative
                    x value will overlap with the preceding letter.
            !*/</font>

            <b><a name='point'></a>point</b> <font face='Lucida Console'>(</font>
            <font face='Lucida Console'>)</font>;
            <font color='#009900'>/*!
                ensures
                    - This constructor does nothing.  The value of x and y 
                      are undefined after its execution.
            !*/</font>

            <b><a name='point'></a>point</b> <font face='Lucida Console'>(</font>
                <font color='#0000FF'><u>signed</u></font> <font color='#0000FF'><u>char</u></font> x_,
                <font color='#0000FF'><u>signed</u></font> <font color='#0000FF'><u>char</u></font> y_
            <font face='Lucida Console'>)</font>;
            <font color='#009900'>/*!
                ensures
                    - #x == x_
                    - #y == y_
            !*/</font>


            <font color='#0000FF'><u>signed</u></font> <font color='#0000FF'><u>char</u></font> x;
            <font color='#0000FF'><u>signed</u></font> <font color='#0000FF'><u>char</u></font> y;
        <b>}</b>;

        <font color='#009900'>// ---------------------------------
</font>
        <b><a name='letter'></a>letter</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - #width() == 0 
                - #num_of_points() == 0 
        !*/</font>

        <b><a name='letter'></a>letter</b> <font face='Lucida Console'>(</font>
            <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>short</u></font> width_,
            <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>short</u></font> point_count
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - #width() == width_
                - #num_of_points() == point_count
        !*/</font>

        ~<b><a name='letter'></a>letter</b><font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - any resources used by *this have been freed
        !*/</font>
            
        <font color='#0000FF'>const</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>short</u></font> <b><a name='width'></a>width</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            ensures
                - returns the width reserved for this letter in pixels.  This is the 
                  number of pixels that are reserved for this letter between adjoining 
                  letters.  It isn't necessarily the width of the actual letter itself.  
                  (for example, you can make a letter with a width less than how wide it 
                  actually is so that it overlaps with its neighbor letters.)
        !*/</font>

        <font color='#0000FF'>const</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>short</u></font> <b><a name='num_of_points'></a>num_of_points</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            ensures
                - returns the number of pixels that make up this letter.
        !*/</font>

        point<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b>[] <font face='Lucida Console'>(</font>
            <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>short</u></font> i
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            requires
                - i &lt; num_of_points()
            ensures
                - returns a non-const reference to the ith point in this letter.
        !*/</font>

        <font color='#0000FF'>const</font> point<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b>[] <font face='Lucida Console'>(</font>
            <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>short</u></font> i
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            requires
                - i &lt; num_of_points()
            ensures
                - returns a const reference to the ith point in this letter.
        !*/</font>

        <font color='#0000FF'><u>void</u></font> <b><a name='swap'></a>swap</b> <font face='Lucida Console'>(</font>
            letter<font color='#5555FF'>&amp;</font> item
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - swaps *this with item
        !*/</font>
    
        <font color='#0000FF'>private</font>:

        <font color='#009900'>// restricted functions
</font>        <b><a name='letter'></a>letter</b><font face='Lucida Console'>(</font>letter<font color='#5555FF'>&amp;</font><font face='Lucida Console'>)</font>;        <font color='#009900'>// copy constructor
</font>        letter<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b><font color='#5555FF'>=</font><font face='Lucida Console'>(</font>letter<font color='#5555FF'>&amp;</font><font face='Lucida Console'>)</font>;    <font color='#009900'>// assignment operator
</font>    <b>}</b>;

    <font color='#0000FF'>inline</font> <font color='#0000FF'><u>void</u></font> <b><a name='swap'></a>swap</b> <font face='Lucida Console'>(</font>
        letter<font color='#5555FF'>&amp;</font> a,
        letter<font color='#5555FF'>&amp;</font> b
    <font face='Lucida Console'>)</font> <b>{</b> a.<font color='#BB00BB'>swap</font><font face='Lucida Console'>(</font>b<font face='Lucida Console'>)</font>; <b>}</b>
    <font color='#009900'>/*!
        provides a global swap
    !*/</font>

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'><u>void</u></font> <b><a name='serialize'></a>serialize</b> <font face='Lucida Console'>(</font>
        <font color='#0000FF'>const</font> letter<font color='#5555FF'>&amp;</font> item, 
        std::ostream<font color='#5555FF'>&amp;</font> out 
    <font face='Lucida Console'>)</font>;   
    <font color='#009900'>/*!
        provides serialization support for letter objects
    !*/</font>

    <font color='#0000FF'><u>void</u></font> <b><a name='deserialize'></a>deserialize</b> <font face='Lucida Console'>(</font>
        letter<font color='#5555FF'>&amp;</font> item, 
        std::istream<font color='#5555FF'>&amp;</font> in
    <font face='Lucida Console'>)</font>;   
    <font color='#009900'>/*!
        provides deserialization support for letter objects
    !*/</font>

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'>class</font> <b><a name='font'></a>font</b>
    <b>{</b>
        <font color='#009900'>/*!
            WHAT THIS OBJECT REPRESENTS
                This object defines an interface for a font type.  It provides metrics
                for the font and functions to help you draw strings on a canvas object.

            THREAD SAFETY
                All the functions in this class are thread safe.
        !*/</font>

    <font color='#0000FF'>public</font>:

        <font color='#0000FF'>virtual</font> <font color='#0000FF'><u>bool</u></font> <b><a name='has_character'></a>has_character</b> <font face='Lucida Console'>(</font>
            unichar ch
        <font face='Lucida Console'>)</font><font color='#0000FF'>const</font><font color='#5555FF'>=</font><font color='#979000'>0</font>;
        <font color='#009900'>/*!
            ensures
                - if (this font has a glyph for the given character) then
                    - returns true
                - else
                    - returns false
        !*/</font>
        <font color='#0000FF'><u>bool</u></font> <b><a name='has_character'></a>has_character</b><font face='Lucida Console'>(</font><font color='#0000FF'><u>char</u></font> ch<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>    <b>{</b> <font color='#0000FF'>return</font> <font color='#0000FF'>this</font><font color='#5555FF'>-</font><font color='#5555FF'>&gt;</font><font color='#BB00BB'>has_character</font><font face='Lucida Console'>(</font>zero_extend_cast<font color='#5555FF'>&lt;</font>unichar<font color='#5555FF'>&gt;</font><font face='Lucida Console'>(</font>ch<font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>; <b>}</b>
        <font color='#0000FF'><u>bool</u></font> <b><a name='has_character'></a>has_character</b><font face='Lucida Console'>(</font><font color='#0000FF'><u>wchar_t</u></font> ch<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <b>{</b> <font color='#0000FF'>return</font> <font color='#0000FF'>this</font><font color='#5555FF'>-</font><font color='#5555FF'>&gt;</font><font color='#BB00BB'>has_character</font><font face='Lucida Console'>(</font>zero_extend_cast<font color='#5555FF'>&lt;</font>unichar<font color='#5555FF'>&gt;</font><font face='Lucida Console'>(</font>ch<font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>; <b>}</b>
        <font color='#009900'>/* Cast char and wchar_t to unichar correctly when char or wchar_t is a signed type */</font>

        <font color='#0000FF'>virtual</font> <font color='#0000FF'>const</font> letter<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b>[] <font face='Lucida Console'>(</font>
            unichar ch
        <font face='Lucida Console'>)</font><font color='#0000FF'>const</font><font color='#5555FF'>=</font><font color='#979000'>0</font>;
        <font color='#009900'>/*!
            ensures
                - if (has_character(ch) == true) then
                    - returns a letter object that tells you how to draw this character.
                - else
                    - returns some default glyph for characters that aren't in this font.
        !*/</font>
        <font color='#0000FF'>const</font> letter<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b>[] <font face='Lucida Console'>(</font><font color='#0000FF'><u>char</u></font> ch<font face='Lucida Console'>)</font>    <font color='#0000FF'>const</font> <b>{</b> <font color='#0000FF'>return</font> <font face='Lucida Console'>(</font><font color='#5555FF'>*</font><font color='#0000FF'>this</font><font face='Lucida Console'>)</font>[zero_extend_cast<font color='#5555FF'>&lt;</font>unichar<font color='#5555FF'>&gt;</font><font face='Lucida Console'>(</font>ch<font face='Lucida Console'>)</font>]; <b>}</b>;
        <font color='#0000FF'>const</font> letter<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b>[] <font face='Lucida Console'>(</font><font color='#0000FF'><u>wchar_t</u></font> ch<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <b>{</b> <font color='#0000FF'>return</font> <font face='Lucida Console'>(</font><font color='#5555FF'>*</font><font color='#0000FF'>this</font><font face='Lucida Console'>)</font>[zero_extend_cast<font color='#5555FF'>&lt;</font>unichar<font color='#5555FF'>&gt;</font><font face='Lucida Console'>(</font>ch<font face='Lucida Console'>)</font>]; <b>}</b>;
        <font color='#009900'>/* Cast char and wchar_t to unichar correctly when char or wchar_t is a signed type */</font>

        <font color='#0000FF'>virtual</font> <font color='#0000FF'>const</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> <b><a name='height'></a>height</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <font color='#5555FF'>=</font> <font color='#979000'>0</font>;
        <font color='#009900'>/*!
            ensures
                - returns the height in pixels of the tallest letter in the font                
        !*/</font>

        <font color='#0000FF'>virtual</font> <font color='#0000FF'>const</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> <b><a name='ascender'></a>ascender</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <font color='#5555FF'>=</font> <font color='#979000'>0</font>;
        <font color='#009900'>/*!
            ensures
                - returns the height() minus the number of pixels below the baseline used
                  by the letter that hangs the lowest below the baseline.
        !*/</font>

        <font color='#0000FF'>virtual</font> <font color='#0000FF'>const</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> <b><a name='left_overflow'></a>left_overflow</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <font color='#5555FF'>=</font> <font color='#979000'>0</font>;
        <font color='#009900'>/*! 
            ensures
                - returns how far outside and to the left of its width a letter
                  from this font may set pixels.  (i.e. how many extra pixels to its
                  left may a font use)
        !*/</font>

        <font color='#0000FF'>virtual</font> <font color='#0000FF'>const</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> <b><a name='right_overflow'></a>right_overflow</b> <font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <font color='#5555FF'>=</font> <font color='#979000'>0</font>;
        <font color='#009900'>/*! 
            ensures
                - returns how far outside and to the right of its width a letter
                  from this font may set pixels.  (i.e. how many extra pixels to its
                  right may a font use)
        !*/</font>

        <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font><font color='#0000FF'>typename</font> T, <font color='#0000FF'>typename</font> traits, <font color='#0000FF'>typename</font> alloc<font color='#5555FF'>&gt;</font>
        <font color='#0000FF'><u>void</u></font> <b><a name='compute_size'></a>compute_size</b> <font face='Lucida Console'>(</font>
            <font color='#0000FF'>const</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font><font color='#5555FF'>&amp;</font> str,
            <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font><font color='#5555FF'>&amp;</font> width,
            <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font><font color='#5555FF'>&amp;</font> height,
            <font color='#0000FF'>typename</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::size_type first <font color='#5555FF'>=</font> <font color='#979000'>0</font>,
            <font color='#0000FF'>typename</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::size_type last <font color='#5555FF'>=</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::npos
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            requires
                - if (last != std::basic_string&lt;T,traits,alloc&gt;::npos) then
                    - first &lt;= last
                    - last &lt; str.size()
            ensures
                - all characters in str with an index &lt; first are ignored by this
                  function.
                - if (last != std::basic_string&lt;T,traits,alloc&gt;::npos) then
                    - all characters in str with an index &gt; last are ignored by 
                      this function.
                - if (str.size() == 0) then
                    - #width == 0
                    - #height == 0
                - else
                    - #width == sum of the widths of the characters in the widest 
                      line in str + left_overflow() + right_overflow(). 
                    - #height == (count(str.begin(),str.end(),'\n')+1)*height()
        !*/</font>

        <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font><font color='#0000FF'>typename</font> T, <font color='#0000FF'>typename</font> traits, <font color='#0000FF'>typename</font> alloc, <font color='#0000FF'>typename</font> pixel_type<font color='#5555FF'>&gt;</font>
        <font color='#0000FF'><u>void</u></font> <b><a name='draw_string'></a>draw_string</b> <font face='Lucida Console'>(</font>
            <font color='#0000FF'>const</font> canvas<font color='#5555FF'>&amp;</font> c,
            <font color='#0000FF'>const</font> rectangle<font color='#5555FF'>&amp;</font> rect,
            <font color='#0000FF'>const</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font><font color='#5555FF'>&amp;</font> str,
            <font color='#0000FF'>const</font> pixel_type<font color='#5555FF'>&amp;</font> color <font color='#5555FF'>=</font> <font color='#BB00BB'>rgb_pixel</font><font face='Lucida Console'>(</font><font color='#979000'>0</font>,<font color='#979000'>0</font>,<font color='#979000'>0</font><font face='Lucida Console'>)</font>,
            <font color='#0000FF'>typename</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::size_type first <font color='#5555FF'>=</font> <font color='#979000'>0</font>,
            <font color='#0000FF'>typename</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::size_type last <font color='#5555FF'>=</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::npos,
            <font color='#0000FF'>const</font> rectangle area <font color='#5555FF'>=</font> <font color='#BB00BB'>rectangle</font><font face='Lucida Console'>(</font><font color='#5555FF'>-</font>infinity,<font color='#5555FF'>-</font>infinity,infinity,infinity<font face='Lucida Console'>)</font>
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            requires
                - if (last != std::basic_string&lt;T,traits,alloc&gt;::npos) then
                    - first &lt;= last
                    - last &lt; str.size()
            ensures
                - all characters in str with an index &lt; first are ignored by this
                  function.
                - if (last != std::basic_string&lt;T,traits,alloc&gt;::npos) then
                    - all characters in str with an index &gt; last are ignored by 
                      this function.
                - if (str.size() == 0) then
                    - does nothing
                - else
                    - draws str on the given canvas at the position defined by rect.  
                      Also uses the given pixel colors for the font color.
                - If the string is too big to fit in rect then the right and
                  bottom sides of it will be clipped to make it fit.                  
                - only the part of the string that is contained inside the area
                  rectangle will be drawn
        !*/</font>

        <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font><font color='#0000FF'>typename</font> T, <font color='#0000FF'>typename</font> traits, <font color='#0000FF'>typename</font> alloc<font color='#5555FF'>&gt;</font>
        <font color='#0000FF'>const</font> rectangle <b><a name='compute_cursor_rect'></a>compute_cursor_rect</b> <font face='Lucida Console'>(</font>
            <font color='#0000FF'>const</font> rectangle<font color='#5555FF'>&amp;</font> rect,
            <font color='#0000FF'>const</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font><font color='#5555FF'>&amp;</font> str,
            <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> index,
            <font color='#0000FF'>typename</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::size_type first <font color='#5555FF'>=</font> <font color='#979000'>0</font>,
            <font color='#0000FF'>typename</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::size_type last <font color='#5555FF'>=</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::npos
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            requires
                - if (last != std::basic_string&lt;T,traits,alloc&gt;::npos) then
                    - first &lt;= last
                    - last &lt; str.size()
            ensures
                - the returned rectangle has a width of 1 and a 
                  height of this-&gt;height().
                - computes the location of the cursor that would sit just before
                  the character str[index] if str were drawn on the screen by
                  draw_string(rect,str,...,first,last).  The cursor location is
                  returned in the form of a rectangle.
                - if (index &lt; first) then
                    - the returned cursor will be just before the character str[first].
                - if (last != std::basic_string&lt;T,traits,alloc&gt;::npos &amp;&amp; index &gt; last) then
                    - the returned cursor will be just after the character str[last]
                - if (str.size() == 0) then
                    - the returned cursor will be just at the start of the rectangle where
                      str would be drawn if it wasn't empty.
                - if (index &gt; str.size()-1) then
                    - the returned cursor will be just after the character str[str.size()-1]
        !*/</font>

        <font color='#0000FF'>template</font> <font color='#5555FF'>&lt;</font><font color='#0000FF'>typename</font> T, <font color='#0000FF'>typename</font> traits, <font color='#0000FF'>typename</font> alloc<font color='#5555FF'>&gt;</font>
        <font color='#0000FF'>const</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> <b><a name='compute_cursor_pos'></a>compute_cursor_pos</b> <font face='Lucida Console'>(</font>
            <font color='#0000FF'>const</font> rectangle<font color='#5555FF'>&amp;</font> rect,
            <font color='#0000FF'>const</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font><font color='#5555FF'>&amp;</font> str,
            <font color='#0000FF'><u>long</u></font> x,
            <font color='#0000FF'><u>long</u></font> y,
            <font color='#0000FF'>typename</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::size_type first <font color='#5555FF'>=</font> <font color='#979000'>0</font>,
            <font color='#0000FF'>typename</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::size_type last <font color='#5555FF'>=</font> std::basic_string<font color='#5555FF'>&lt;</font>T,traits,alloc<font color='#5555FF'>&gt;</font>::npos
        <font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>;
        <font color='#009900'>/*!
            requires
                - if (last != std::basic_string&lt;T,traits,alloc&gt;::npos) then
                    - first &lt;= last
                    - last &lt; str.size()
            ensures
                - returns a number idx that has the following properties:
                    - if (first &lt; str.size()) then
                        - first &lt;= idx
                    - else
                        - idx == str.size()
                    - if (last != std::basic_string&lt;T,traits,alloc&gt;::npos) then
                        - idx &lt;= last + 1
                    - compute_cursor_rect(rect,str,idx,first,last) == the cursor
                      position that is closest to the pixel (x,y)
        !*/</font>


    <font color='#0000FF'>private</font>:

        <font color='#009900'>// restricted functions
</font>        <b><a name='font'></a>font</b><font face='Lucida Console'>(</font>font<font color='#5555FF'>&amp;</font><font face='Lucida Console'>)</font>;        <font color='#009900'>// copy constructor
</font>        font<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b><font color='#5555FF'>=</font><font face='Lucida Console'>(</font>font<font color='#5555FF'>&amp;</font><font face='Lucida Console'>)</font>;    <font color='#009900'>// assignment operator
</font>    <b>}</b>;

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'>class</font> <b><a name='default_font'></a>default_font</b> : <font color='#0000FF'>public</font> font
    <b>{</b>
        <font color='#009900'>/*!
            WHAT THIS OBJECT REPRESENTS
                This is an implementation of the Helvetica 12 point font.

            THREAD SAFETY
                It is safe to call get_font() and access the returned font from any 
                thread and no synchronization is needed as long as it is called 
                after the main() function has been entered.
        !*/</font>

    <font color='#0000FF'>public</font>:
        <font color='#0000FF'>static</font> <font color='#0000FF'>const</font> shared_ptr_thread_safe<font color='#5555FF'>&lt;</font>font<font color='#5555FF'>&gt;</font> <b><a name='get_font'></a>get_font</b><font face='Lucida Console'>(</font>
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - returns an instance of this font.
            throws
                - std::bad_alloc
                    This exception is thrown if there is a problem gathering the needed
                    memory for the font object.
        !*/</font>

    <font color='#0000FF'>private</font>:

        <font color='#009900'>// restricted functions
</font>        <b><a name='default_font'></a>default_font</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;        <font color='#009900'>// normal constructor
</font>        <b><a name='default_font'></a>default_font</b><font face='Lucida Console'>(</font>default_font<font color='#5555FF'>&amp;</font><font face='Lucida Console'>)</font>;        <font color='#009900'>// copy constructor
</font>        default_font<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b><font color='#5555FF'>=</font><font face='Lucida Console'>(</font>default_font<font color='#5555FF'>&amp;</font><font face='Lucida Console'>)</font>;    <font color='#009900'>// assignment operator   
</font>    <b>}</b>;

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'>class</font> <b><a name='bdf_font'></a>bdf_font</b> : <font color='#0000FF'>public</font> font
    <b>{</b>
    
        <font color='#009900'>/*!
            WHAT THIS OBJECT REPRESENTS
                This is a font object that is capable of loading of loading BDF (Glyph 
                Bitmap Distribution Format) font files.

            THREAD SAFETY
                If you only access this object via the functions in the parent class font 
                then this object is thread safe.  But if you need to call any of the
                functions introduced in this derived class then you need to serialize 
                access to this object while you call these functions.
        !*/</font>

    <font color='#0000FF'>public</font>:

        <b><a name='bdf_font'></a>bdf_font</b><font face='Lucida Console'>(</font> 
            <font color='#0000FF'><u>long</u></font> default_char <font color='#5555FF'>=</font> <font color='#5555FF'>-</font><font color='#979000'>1</font> 
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - for all x:
                    - #has_character(x) == false
                      (i.e. this font starts out empty.  You have to call read_bdf_file()
                      to load it with data)
                - if (default_char == -1) then
                    - the letter returned by (*this)[ch] for values of
                      ch where has_character(ch) == false will be the
                      default glyph defined in the bdf file.
                - else
                    - the letter returned by (*this)[ch] for values of
                      ch where has_character(ch) == false will be the
                      letter (*this)[default_char].
        !*/</font>
    
        <font color='#0000FF'><u>long</u></font> <b><a name='read_bdf_file'></a>read_bdf_file</b><font face='Lucida Console'>(</font> 
            std::istream<font color='#5555FF'>&amp;</font> in, 
            unichar max_enc, 
            unichar min_enc <font color='#5555FF'>=</font> <font color='#979000'>0</font> 
        <font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - attempts to read the font data from the given input stream into
                  *this.  The input stream is expected to contain a valid BDF file.
                - reads in characters with encodings in the range min_enc to max_enc
                  into this font.  All characters in the font file outside this range
                  are ignored.
                - returns the number of characters loaded into this font from the
                  given input stream.
        !*/</font>

        <font color='#0000FF'><u>void</u></font> <b><a name='adjust_metrics'></a>adjust_metrics</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
        <font color='#009900'>/*!
            ensures
                - Computes metrics based on actual glyphs loaded, instead of using 
                  the values in the bdf file header. (May be useful if loading glyphs 
                  from more than one file or a small part of a file.)
        !*/</font>

    <font color='#0000FF'>private</font>:
    
        <b><a name='bdf_font'></a>bdf_font</b><font face='Lucida Console'>(</font> bdf_font<font color='#5555FF'>&amp;</font> <font face='Lucida Console'>)</font>;      <font color='#009900'>// copy constructor
</font>        bdf_font<font color='#5555FF'>&amp;</font> <b><a name='operator'></a>operator</b><font color='#5555FF'>=</font><font face='Lucida Console'>(</font> bdf_font<font color='#5555FF'>&amp;</font> <font face='Lucida Console'>)</font>;  <font color='#009900'>// assignment operator
</font>    
    <b>}</b>;

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
    <font color='#0000FF'>const</font> shared_ptr_thread_safe<font color='#5555FF'>&lt;</font>font<font color='#5555FF'>&gt;</font> <b><a name='get_native_font'></a>get_native_font</b><font face='Lucida Console'>(</font>
    <font face='Lucida Console'>)</font>;
    <font color='#009900'>/*!
        ensures
            - returns a font object that uses the local font
    !*/</font>

<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
<b>}</b>

<font color='#0000FF'>#endif</font> <font color='#009900'>// DLIB_FONTs_ABSTRACT_
</font>

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